Field of Invention and Prior Art
This invention relates to harvesting apparatus and process and is particularly directed to apparatus and process for harvesting fruit from fruit-bearing trees.
With the development of abscission-promoting materials such as ACTI-AID.sup.TM, mechanical harvesters designed to shake the limbs of a tree have been developed. Effective such mechanical harvesters are provided with means for causing blasts of air to impinge on fruit-bearing limbs to set them in motion to shake the fruit from the limbs. U.S. Pat. No. 3,943,688, for example, discloses a harvesting machine of the class described with louvers adapted to direct air blasts upwardly or downwardly either in unison or in non-unison. Also, U.S. Pat. No. 3,871,040 discloses a harvester for directing pulsating jets of compressed air into the tree. U.S. Pat. No. 3,757,504 discloses parallel vertical columns having means therein to direct blasts of air toward the center of the tree with means to cause the air to be directed upwardly or downwardly in a random manner for the height of each column. U.S. Pat. No. 3,310,231 is similar to U.S. Pat. No. 3,943,688, but uses the means of U.S. Pat. No. 3,757,504 for causing the blast or jet of air to be directed upwardly or downwardly in a random manner.
U.S. Pat. No. 3,114,998 discloses a harvesting means for directing jets of air downwardly, sideways, and upwardly into the tree, and U.S. Pat. No. 3,455,502 discloses means for directing a high-velocity blast of air into the top of the tree to knock the fruit therefrom into a wagon.
Still another harvester which employs a pulsating air blast to remove oranges that have been treated with an abscission chemical, is disclosed in The Citrus Industry, Vol. 57, August 1976, page 15. Three fans are stacked vertically and are powered in a way, not shown, to produce a pulsating air blast.
The prior art does not disclose the salient features of this invention, which will be described more particularly below, of causing a blast of air to impinge on a fruit-bearing limb grouping, that is, one or more limbs affected by the blast of air, to cause the limb grouping to bend, and thereafter causing a blast of air from the opposite direction to impinge on the limb grouping while it is still bent as a result of the first blast of air.